Cummins/Onan 6.3 NHEL / 6.5 NH — Slip Ring Service
Maintenance · Slip rings
For the Cummins/Onan 6.3 NHEL / 6.5 NH, from the Cummins/Onan service manual.
Applies to: Cummins/Onan NHEL
Before you start
- Contact with rotating machinery can cause severe personal injury. Keep hands and fingers clear while servicing slip rings.
Procedure
- Remove the air cleaner cover and air cleaner filter.
- Disconnect the lead wires from the brush block terminals and insulate the lead wire ends; tie leads to one side.
- Remove the brush block mounting screws and lift out the brush block.
- Remove K1-S lead wire from the S terminal on the K1 start solenoid; connect a pushbutton switch in series between the K1-S lead wire and the S terminal.
- Place a jumper wire between remote connector plug terminals 1 and 3.
- Press the pushbutton switch to crank the engine; release as soon as the engine starts.
- Hold commutator stone (Onan tool #420-0259) against rotating slip rings until carbon is removed and grooves or roughness is smoothed out.
- Remove jumper wire from remote connector plug.
- Remove insulating material from brush lead wire ends and install brush block.
Tools required
- Onan tool #420-0259 commutator stone Amazon
- Pushbutton switch (normally open) Amazon
- Jumper wire Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Cummins/Onan NHEL →
Source: Cummins/Onan service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.